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May 2010

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You can tell from the frequency of recent blog harvests that we are slightly overloaded with work at the moment. This is a rather preferred state to be in as a small contract development company, but everything not ultimately necessary is reduced during those phases. We consider blog reading as indispensable, but reporting the best of articles (our blog harvest) isn’t. So right now, we have a very long list of articles in our harvest barn. Here are some articles of the last two months:

Does Groovy Know You Are Seeing Clojure? – A real world story of learning Clojure, the Functional Programming language on top of the JVM. I can wholeheartly agree with the sentence “In the intervening 30 years since starting out on a TRS-80 Model 1 nothing has been more difficult in terms of solving even the most trivial of problems than learning Clojure.”, but in my case, it has been a little more than 15 years of real experience. After a year trying to “get” Clojure, I deferred it for more productive work.

Don’t return null; use a tail call – A blog entry about the billion-dollar-mistake (null pointers) and API design. It got inspired by Steve Freeman’s book “Growing Object-Oriented Software” (see next section for more content by Steve Freeman). The idea of “tail calls” or callbacks isn’t new or revolutionary, but widely underused. Personally, I found the idea of returning empty Iterables (as an abstract commonplace of Collections) useful in some scenarios.

Practical Styles of Pair Programming – First hand experiences of a pair programming enthusiast (Iwein Fuld). His scenarios seem familiar and the advices given reasonable. Reading the article sharpened my awareness about pair programming. There is only one complaint about the article from my side: Using headphones while programming doesn’t turn you into a zombie, it just eliminates the outer world for some time. That’s Alone Time, and it’s there for a reason, too.

Java1.6u18 and double array creation – A little story about flawed unit tests, recent java improvements and the value of nightly builds. Thanks for sharing this with the world, David Shay.

Do You Like Pain? – Jared Richardson shares his story and advice about getting used to the “pain” in any environment. I like the idea of the “prisoner swap” to identify pain points a lot. But from my own experience I can tell that the messenger might be muted by labelling him “not fully aware”.

Java Post Mortem with Gilad Bracha – A post mortem should only be done on “dead” people/projects. So the title alone is a harsh statement. But the summary of the talk contains some valid points and a lot of opinions to think about. I particularly like the term “cottage industry” for DI framework vendors.

Next comes the video section of this blog harvest. I’ve found the time invested in these talks worthwhile:

Threading is not a model (35min) – Joe Gregorio presents the lack of advanced multiprocessing tools in most programming languages. His talk covers a lot more than just that and gives some appetizers on Python. The solicited lack of MP support was my reason to learn Clojure (see first entry in the list above).

Sustainable Test-Driven Development (55min) – Steve Freeman gives a whole bunch of advanced tips to write unit tests. The talk is given from the TDD/BDD point of view, but mostly applies to unit tests in general. You should be familiar with JUnit to fully understand this talk.

And at last, there is a tool I want to present you (this kind of resembles the fun section, too):

Dollar – An experimental java API that shows how much you can bend the java syntax to suit your personal taste. Through inspiration by this project I’ve come to some unique ways to make my code more expressive – without using funny signs. Thanks to Davide Angelocola for his unique approach.

Last friday, we held our Open Source Love Day for May 2010. After the excessive yak shaving of last month’s OSLD, this one was more productive. We got one feature right nearly instantly and several others throughout the day. To keep us from feeling depressed, we allocated dedicated “research time” to get to know a project before starting to develop on it. So one point on our current list of accomplishments is only research work that should be counted as “thought investment” for further improvements.

The Open Source Love Day

We introduced a monthly Open Source Love Day (OSLD) to show our appreciation to the Open Source software ecosystem and to donate back. We heavily rely on Open Source software for our projects. We would be honored if you find our contributions useful. Check out our first OSLD blog posting for details on the event itself.

On this OSLD, we accomplished the following tasks:

Netty is a java framework to perform network communication, transparently using different transport mechanisms. We use it in a customer project environment and it worked mostly well. But we noticed some issues that might have to do with the framework, so we decided to put it under development. But before hopping in right away, we invested some hours to really anatomize it. Our achievement isn’t noticeable yet, but might be in the future.

Launch4j is a java application launcher for Windows, handling all the stuff a startup script (the infamous start.bat) would do, too. One thing that’s easy to perform in a batch script is to restart the application if it went down with an error. We wanted this feature in Launch4j and we succeeded. Before releasing the changes to the project, we need some rethinking of our approach, as it is very special to our case, but if you are interested, we send you the patch on request.

RXTX is a project to perform serial (RS232) communication. Over the course of the last OSLDs, we worked on an issue that appears in combination with serial converters. See the OSLD posting for march 2010 for details. This issue seems to be completely fixed now. We will run some longterm stability tests with it and then release a patch to the issue tracker of RXTX, issue #144.

Our internal tool for business administration was greatly improved this time. The tool isn’t open sourced yet, but we are not afraid to publish it in the future. The new features will directly decrease our administrative overhead and give us more time to perform our main duty – developing software.

Our monthly “Homepage Comittee” meeting went smooth this time. The setup pain of last month is now paying out and we got our homepage updated. It seems the yaks haven’t grown beards again yet.

What were our lessons learnt today?

Pure C code tends to produce endless code blocks. Simple refactorings like extract method/function take a long time and aren’t supported by the IDE. The sentence “there is no boolean!” left some of us impressed, too.

The C/C++ Eclipse workbench (in fact, a bunch of plugins for Eclipse) was a joke instead of a help. It didn’t exactly prevent us from doing our work, but that’s all it did. Launch4j came along with project files for the Bloodshed Dev-C++ IDE, which – besides its bloody name – seems to be up to its tasks. We decided to use Dev-C++ over Eclipse for development on Launch4j.

Hpricot is a very versatile HTML parser/manipulator. It is just pure joy to work with. (Ok, we knew that one before)

After the fruitless OSLD of april, this one was a great relief for us. The new restart feature for Launch4j worked out instantly and will solve many of our current immediate problems (and some of yours, hopefully). The solution for RXTX got us out of trouble, too. All in all, this was a successful OSLD.

Last sunday, we held our Dev Brunch for May 2010. It was a small group of developers brunching together this time. One reason was a communication failure on my part, as a crucial email announcing a change in the appointment didn’t reach everyone interested in participating. Sorry for this one again! The other reason was more of a pleasure: Two of our regular brunch attendees are turning into parents. But a core group brunched and talked in the office roof garden, discussing the topics listed below.

Options in Scala – If you are used to traditional programming languages like Java, you might be surprised that you can’t nullify a reference in Scala. There is no concept of “null” in Scala, therefore avoiding the so-called billion dollar mistake (you might want to listen to the guy who invented the mistake, too). If you want to use “uncertain” references, you should look into the Option type of Scala, which was the main topic of this talk. With some code examples, this was a decent introduction into the concept.

Summary of the Sensor+Test trade fair – This talk was a short report of the recently visited german Sensor+Test measurement fair in Nuremburg. Details may follow on this blog, but the overall summary is that the measurement industry in Germany and neighbours is mostly self-confident and down-to-earth.

The Modbus protocol - This talk was a short introduction to the ancient (but still useful) Modbus protocol and the possibilities to access it in Java. There are at least two projects that provide full coverage of the protocol: jamod and modbus4j. The protocol itself is rather low-level, but sufficient for simple control and data query tasks on an embedded device. The possibility to be mostly agnostic over the physical transport layer is a strength of the Modbus protocol and its implementations.

As usual, the topics ranged from first-hand experiences and impressions to literature reviews and research. For additional information provided by the talk authors, check out the comment section (or leave a comment to request further content). Comments and resources might be in german language.

Retrospection of the brunch

The usual brunch setup is nearly perfect. What was lacking this time was the coordination of the appointment. To further improve on that point, we introduced a new mailing list, containing everone that is currently interested in participating the brunch.